*{
    margin: 0;
    padding: 0;
}
html, body{
    height: 100%;
    width: 100%;
}
.root {
    height: 100%;
    width: 100%;
    display: flex;
    flex-direction: column;
    background-color: #fff;
}
.title {
    height: 50px;
    display:table-cell;
    vertical-align:middle;
    text-align:center;
}
.item {
    display: inline-block;
    width: 10%;
    height: 50px;
    background-color: #fff;
}
a {
    display: block;
    height: 50px;
    margin: auto 0;
    text-decoration: none;
    text-align: center;
    background-color: #fff;
    line-height: 50px;
    font-size: 16px;
    color: #000;
}
a:hover {
    color: #2e7fff;
    background-color: #e0e0e0;
}
.course {
    height: 60%;
    background-color: #fffc2a;
    display: flex;
}
.course .item1,.item3{
    width: 20%;
    background-color: #f5f5f5;
}
.course .item2{
    flex: 1;
}

.zhe {
    flex: 1;
    background-color: #fff;
}